Electric switches



Sept. 19, 1967 ANGOLD 3,134.2;969

ELECTRI C SWITCHES Filed Jan. 24, 1966 United. States Patent .0

3,342,969 ELECTRIC SWITCHES Edward B. Angold, Emsworth, England,assignor to The Plessey Company Limited, Ilford, England, a Britishcompany Filed Jan. 24, 1966, Ser. No. 578,418 Claims priority,application Great Britain, Jan. 27, 1965,

3,616/ 65 Claims. (Cl. 200-466) ABSTRACT OF THE DISCLOSURE An electricswitch having a pair of juxtaposed arms each having on one end V-shapedparts which lie side by side and are mutually embraced by one end of acoil spring and carry on their other opposing ends respectively movingcontacts, the switch being actuable by means of a plunger operable forcompressing the coil spring so that the pair of arms are moved in thedirection of movement of the plunger thereby to urge the moving contactsinto co-operation with a complementary set of fixed contacts.

This invention relates to electric switches.

According to the present invention an electric switch comprises at leasttwo sets of contacts, the moving contacts of which are carried byseparate pivoted arms which are acted on by a spring common to both armsat the common pivoting point of said arms.

Electric switches constructed according to the invention may readily bearranged so that one of the sets of contacts is operated before theother.

The moving contact-carrying arms may comprise V- shaped portions at ornear the ends thereof remote from the moving contacts, which portionsmay be embraced by one end of a coil spring which provides in effect adisplaceable pivot for the moving arms since in response to theoperation of the switch by compression of the coil spring the pivotpoint of the two arms is moved in the direction of movement of anactuating plunger of the switch.

The moving contacts may comprise bridging contacts arranged to bridgerespective pairs of fixed contacts and taking the form of rods whichextend transversely to the direction of movement of the contacts throughholes provided in the arms so that the moving contacts are a loose fitin these holes and can therefore swivel through a limited angle in orderto afford equalisation of contact pressure between the moving andco-operating fixed contacts consequent upon the operation of the switch.

By way of example, the present invention will now be described withreference to the accompanying drawing in which:

FIGURE 1 is a somewhat diagrammatic sectional view taken through anelectric switch constructed in accordance with the invention;

FIGURE 2 is a diagrammatic view of the switch mechanism taken in thedirection A in FIGURE 1; and

FIGURE 3 is a view of the switch actuating plunger and loading spring ofthe switch of FIGURE 1.

Referring to the drawing, the switch comprises two sets of electriccontacts, each set consisting of pairs of spaced apart fixed contacts 1,2 and 3, 4 and co-operating moving bridging contacts 5 and 6. Thebridging contacts 5 and 6 are carried respectively by arms 7 and 8 ofinsulating material the contacts taking the form of rods which extendloosely through holes in the arms so that the rod contacts are free toswivel through a restricted angle and thereby providing equal contactpressures when bridging the fixed contacts 1, 2 or 3, 4 in response tooperation of the switch. The moving contact carrying arms 7 and 8 arelocated in slots extending through a body moulding of the switch. Thesearms 7 and 8 have V-shaped portions 9 and 10 at the ends thereof remotefrom the moving contacts 5 and 6. These V-shaped portions are embracedby the top end of a coil spring 11 which is accommodated within acylindrical opening in the body moulding and which in effect provides amovable pivot for the arms 7 and 8. The coil spring 11 exerts upwardpressure on the arms 7 and 8 maintaining the arms in the positionindicated in FIGURE 1 in the unoperated condition of the switch. It willbe noticed that the depth of the arm 8 is greater than that of the arm 7and consequently the pressure exerted by the spring on the respectivearms can be adjusted by adjustment of the respective widths of the twoarms and by such adjustment it can be arranged that the moving contacts5 and 6 bridge their co-operating fixed contacts sequentially.

For the actuation of the moving contacts 5 and 6 a plunger 12, as can beseen in FIGURE 3, is provided. This plunger which is located in a slotprovided in the body moulding has a generally U-shaped part 13 whichstraddles the coil spring 11 and which bears against the V-shapedportions 9 and 10 of the arms 7 and 8. By depression of the plunger 12the pivot point of the arms 7 and 8 is eifectively lowered causing thearms 7 and 8 to be moved downwardly and upon the moving contact engagingwith the co-operating fixed contacts the arms pivot towards one anotherabout the top-end of the coil spring.

Switches according to the present invention are of simple and relativelyinexpensive construction and sequential operation of the switch contactscan be readily provided. Moreover, a single coil spring only is requiredin respect of a plurality of sets of bridging contacts.

Although the switch described has general application it is eminentlysuitable for use in record players as the mains switch arranged to beoperated at appropriate intervals by the player mechanism.

What I claim is:

1. An electrical switch comprising at least two sets of co-operatingcontacts, at least two fixed contacts incorporated in each set, at leasttwo moving contacts incorporated in each set, a pivoted arm incorporatedin each set, to one end of which the moving contacts are secured, ashaped portion on the other end of each pivoted arm remote the movingcontacts, a coil spring one end of which is arranged to embrace theshaped portions of each pivoted arm to provide in effect a displaceablepivot point for each of said arms, and an actuating plunger co-operatingwith the said shaped portions of said arms for compressing the coilspring and to actuate the switch.

2. An electric switch as claimed in claim 1 wherein the moving contactsof at least one of said sets are electrically interconnected.

3. An electric switch as claimed in claim 2 wherein the electricallyinterconnected moving contacts comprise a rod, a hole being provided inthe pivoted arm through 3 4- which the rod extends so as to project fromeach end coil spring and to co-operate with the said V-shaped porthereoftransversely to the direction of movement of the tions, to form a knifeedge fulcrum.

moving contacts and in which hole said rod is loosely References Citedfitted.

4. An electric switch as claimed in claim 3 comprising 5 UNITED STATESPATENTS pivoted arms having differing depths in the axial direction3,200,225 8/1965 Lernke 200-466 of the coil spring. 3,272,949 9/ 1966Lawrence 200-166 5. An electric switch as claimed in claim 4 wherein theshaped portions of the pivoted arms are V-shaped, and ROBERT SCHAEFERPnmary Exammer' wherein the actuating plunger is arranged to straddlethe 10 H. O. JONES, Assistant Examiner.

1. AN ELECTRICAL SWITCH COMPRISING AT LEAST TWO SETS OF CO-OPERATINGCONTACTS, AT LEAST TWO FIXED CONTACTS INCORPORATED IN EACH SET, AT LEASTTWO MOVING CONTACTS INCORPORATED IN EACH SET, A PIVOTED ARM INCORPORATEDIN EACH SET, TO ONE END OF WHICH THE MOVING CONTACTS ARE SECURED, ASHAPED PORTION ON THE OTHER END OF EACH PIVOTED ARM REMOTE THE MOVINGCONTACTS, A COIL SPRING ONE END OF WHICH IS ARRANGED TO EMBRACE THESHAPED PORTIONS OF EACH PIVOTED ARM TO SHAPED PORTIONS OF SAID ARMS FORCOMPRESSING THE COIL PROVIDE IN EFFECT A DISPLACEABLE PIVOT POINT FOREACH OF SAID ARMS, AND AN ACTUATING PLUNGER CO-OPERATING WITH THE SAIDSPRING AND TO ACTUATE THE SWITCH.